If you've been staring lustfully at an electric motorcycle but needed that little extra push to make the jump, Zero Motorcycles has a unique incentive in store: it'll pay for your first 25,000 miles on the road. Should you take the keys to any one of the company's two-wheelers between now and the end of May, you'll get a Visa gift card for the amount within a few weeks. Of course, the reason it can make such a seemingly generous offer is through the sheer efficiency of an electric engine: at a typical 10 cents for every kilowatt-hour, you're looking at just under $200 for what's li